@book{94736,
	author = {Research co-ordination meeting on Recent developments in the use of Nitrogen-15 in soil plant studies Sofia, Dec.1-5,1969.},
	title = {Nitrogen-15 in soil plant studies; proceedings.},
	publisher = {IAEA},
	year = {1971},
	series = {Panel proceeding series},
	address = {Vienna}
}